Higher June 2018 Paper 3 Q17
17

Work out the length of \(AD\).
Give your answer correct to 3 significant figures. (5)
| Answer | Mark | Mark scheme |
|---|---|---|
| 13.1 | P1 | for start of process to find the length of \(BD\), eg \(\dfrac{BD}{\sin 34^\circ} = \dfrac{12.5}{\sin 109^\circ}\) |
| P1 | for complete process to find the length of \(BD\), eg \(BD = \dfrac{12.5}{\sin 109^\circ} \times \sin 34^\circ\) (= 7.39...) | |
| P1 | for process to find the length of \(AD\), eg \(AD^2 = 11.4^2 + \text{``}7.39^2\text{''} - 2 \times 11.4 \times \text{``}7.39\text{''} \times \cos 86^\circ\) | |
| P1 | for process to use correct order of operations, eg \(129.96 + 54.6(5...) - 11.7(5...)\) (= 172.85...) | |
| A1 | for answer in the range 13.1 to 13.2 |
Additional guidance
Accept 7.4 for the award of the first two P marks
If an answer is given within the range and then incorrectly rounded to 3 sig figs award full marks.